Cancer

Cancer (European Portuguese) or Cancer (Brazilian Portuguese), is a disease characterized by a population of cells that grows and sedivide without observing the normal limits, invades and destroys adjacent tissues, and may spread to distant places in the body, through a process called metastasis. These malignant properties of cancers differentiate them from benign tumors, which are self-limited in their growth and does not invade adjacent tissue (although some benign tumors are capable of becoming malignant). Cancer can affect people of all ages, but the risk for most types of cancer increases with increasing age. Cancer causes about 13% of all deaths worldwide, including cancers of the lung, stomach, liver, colon and mamaos biggest killers.

Physicians of ancient Egypt (3000 BC) recorded diseases, given their characteristics, could probably be classified as cancer. Hippocrates (377 BC) also described illnesses that resemble the cancers of the stomach, rectum, breast, uterus, skin and other organs. Therefore, the presence of cancer in humanity has been known for millennia. However, records that describe the cause of death as cancer came into existence in Europe only from the eighteenth century. Since then, there was a steady increase in cancer mortality rates, which seem to become more pronounced after the nineteenth century with the arrival of industrialization.

Nearly all cancers are caused by abnormalities in the genetic material of the transformed cells. These abnormalities may be due to the effects of carcinogens, such as tobacco smoke, radiation, chemicals, or infectious agents. Other types of gene abnormalities can be acquired through errors in DNA replication, or are inherited, and thus present in all cells from birth. The complex interactions between carcinogens and the host genome may explain why only some develop cancer after exposure to a known carcinogen. New aspects of the genetics of cancer pathogenesis, such as DNA methylation, and microRNAs are increasingly being recognized as important to the process.

Genetic abnormalities found in cancer typically affect two general classes of genes. The cancer-promoting genes, oncogenes are typically activated in cancer cells, providing these cells new properties, such as hyperactive growth and division, protection against programmed cell death, loss of respect for normal tissue boundaries, and the ability to become stable in various tissue environments. The tumor suppressor genes are often inactivated in cancer cells, resulting in loss of normal functions in those cells, such as accurate DNA replication, control over the cell cycle, orientation and adhesion in tissues and interaction with protective cells of the immune system.

The cancer is generally classified according to the material of which the cancer cells originate as well as normal cell type that most closely resemble. A definitive diagnosis usually requires histological examination of biopsy tissue by umpatologista, although the initial indication of malignancy can be symptoms or radiographic imaging abnormalities. Most can be treated and some ripened, depending on the specific type, location and stage. Once diagnosed, cancer is usually treated with a combination of surgery, chemotherapy and radiotherapy. With the development of research, treatments are becoming more specific for different varieties of cancer. Lately there has been significant progress in the development of targeted therapy drugs that act specifically on detectable molecular abnormalities in certain tumors, and which minimize damage to normal cells. The prognosis for patients with cancer is greatly influenced by the type of cancer, as well as the stage, or extent of disease. In addition, the histological grade and the presence of specific molecular markers can also be useful in establishing the prognosis as well as in determining individual treatments.

Prognosis

Cancer has a reputation for being a deadly disease. While this is true for some particular types of cancer, the truths behind the historical connotations of cancer are increasingly being overturned by advances in medical care. Some cancers have a prognosis that is substantially better than other non-malignant diseases such as heart failure and stroke.

A progressive and disseminated malignant disease has a substantial impact on patient quality of life, and many cancer treatments (such as chemotherapy) may have severe side effects. In the advanced stages of cancer, many patients need extensive care, affecting family members and friends.

Patients with cancer for the first time in the history of oncology, are visibly returning to their normal lives. Patients are living longer with the disease lingering but silenced or even complete remission. The stories like Lance Armstrong, who won the Tour de France after treatment of a metastatic testicular cancer or Tony Snow, who was working as press secretary of the White House in the United States despite its colon cancer, remain an inspiration for cancer patients worldwide.

Treatment

The difficulties of cancer treatment is to distinguish between malignant cells and normal cells of the body. Both are from the same origin are very similar and hence no significant recognition by the immune system of the threat.

Surgery

If the mass is well defined and minimally invasive, surgical resection is possible, but it is impossible if the tumor is found throughout the body, or vital organs that can not be cut. It is often difficult for the surgeon to determine the range in which the tumor ends and normal tissue begins with the risk of cutting too much normal tissue and reduce the probability of survival of the patient to the operation or not to remove the cancerous mass in full, decreasing the probability of survival to cancer.

The operation is then only used in the treatment of tumors which are still enclosed by removing the organ resection or complete (prostatectomy in prostate cancer, breast lumpectomy in). However, if the tumor invading structures adjacent resectadas can not be (eg a major artery) is the tumor irressectável.

Chemotherapy

Is based on the fact that tumor cells divide much faster than normal cells. The patient receives drugs (intravenous, orally, in cavities such as the bladder, the intrathecal space, the pleural cavity or abdomen) that interfere with DNA synthesis and kills dividing cells. However, side effects may occur (side) in those fast-growing normal cells such as gastrointestinal mucosa (diarrhea, nausea, vomiting), hair follicles (hair loss) and others. More recently, there is a new class of drugs called monoclonal antibodies, that by having a specific molecular target in cancer cells, have the advantage of being less toxic to normal cells. Monoclonal antibodies can be used alone or in conjunction with chemotherapy.

Radiotherapy

Also attacks fast growing cells. Tumor cells, as they have protein deficit repairing DNA, are more vulnerable to doses of high-energy radiation (X-rays and gamma). Their lethal doses are lower than those of normal cells. However beyond similar side effects of chemotherapy, there risk of developing new tumors, although relatively small.

Hormone Therapy

The growth of some cancers can be inhibited by supplying or blocking certain hormones. Common examples of hormone-responsive tumors include certain types of breast and prostate. Removing or blocking estrogen or testosterone is often an important additional treatment. In certain cancers, administration of hormonal agonists such as progestin may be therapeutically beneficial.

New techniques

Have recently been developed some specific drugs which decrease activity of some proteins (translated oncogenes) which is highly active in the proliferation of some types of cancer.

Chronic myeloid leukemia is curable even by the administration of this new type of drug. In the future these drugs should be more relevant.

The use of toxin-specific antibody coupled to common membrane proteins on the surface of tumor cells but not normal cells has also had some success.

Alternative Therapies

Alternative therapies and non-Westerners are often chosen by many patients whose prognosis is bleak and high costs. However, there is some evidence that these therapies improve prognosis. While also are generally not harmful, they can be made by those who believe parallel to conventional opioid treatment.

If the patient's informed choice, and although probably not have any direct effect, alternative therapies can have a placebo effect, or the patient believes will improve and it is proven that patients are more optimistic and fighters best course of their disease the defeatists. Replace conventional treatment by alternative however would be highly inadvisable, since modern medicine can already improve prognosis and even cure many forms of cancer, and it is impossible to say for sure how a patient will respond to conventional therapy.

However, we should always think about the patient. If the malignancy has already been treated with surgery, chemotherapy and radiotherapy and showed no improvement, doctors have a duty to seek new strategies. Many consider immunotherapy and hyperthermia on complementary credible. There are many scientific good level that attest to the effectiveness of such strategies. On the other hand, many people are cured of tumors using herbal medicine. In fact many drugs of conventional medicine were synthesized from the active ingredients found in the plant kingdom and empirical use. There are also many others who are treated and cured with psychotherapeutic strategies and even acupuncture. The patient has the right to choose the doctor and the duty to offer serious alternatives already studied and secure